outdoor low-voltage lighting

Low-voltage outdoor lighting uses 12 volt instead of the common household 110/120 volts. Low-voltage is cheap and easy to install and can be an energy-efficient option.

Low-voltage outdoor lighting is a simple way to illuminate walkways and other landscape features at night.

Low-voltage Energy-Efficiency

Low-voltage lighting systems aren't necessarily low-energy lighting systems. That's a common misconception. Low-voltage doesn't mean low-wattage...

The efficiency of a low-voltage system depends on the type of lamps and their wattage, and also on lighting controls (timers, photocells...) associated to them.

Low-voltage outdoor kits

There are pre-packaged kits low-voltage outdoor kits comprising a transformer (or power back) with a timer, cables and lights for complete installation.

Common pre-packaged kits are often designed to be expanded: you can add lights in the future, or purchase a second (and a third…) kit to expand a previous system. These kits are often geared for the do-it-yourselfer.

Prices

Prices of some inexpensive kits range from $15 to $100, but the best ones can costs $300 and more, depending on the number and type of lights. Kits using fluorescent and LED lights are typically more expensive (and also the best for energy-efficiency).

Be aware: very low prices usually mean low-quality, energy-inefficiency and environmentally-unfriendly solutions. On the long run, a low initial investment can become an expensive mistake.

Lamps

Halogen lamps are the most common type of lamps used in low-voltage systems. The low-wattage of these lamps (often 4 to 7 watts) can make the system relatively energy-efficient.

But the market is now also offering low-voltage systems using the new LED (Light Emitting Diods) and fluorescent (CFL) lamps, which are more efficient (though also more expensive) - and more advantageous, if lights are on for more than just some short periods.

In the case of fluorescent lights, be sure that they are designed to support outdoor uses and, if that is your case, low temperatures. See Compact Fluorescent Lamps.

Quality Kits

Be aware with the quality of low-voltage products. Prefer Energy Star and European Union Eco-labelled qualified systems; or systems supported by organizations like the The International Dark Sky Association or the Underwriters Laboratories. These products may involve higher initial costs, but they have quality and durability, besides being much more environmentally-friendly.

Outdoor lighting elements should be water-resistant and rated for outdoor use.

Transformers (Power-Backs) and outlets

Outdoor Low-Voltage Low-voltage transformers are designed to plug into standard outlets in order to reduce the 110/120 volts household current to 12 volts.

Most transformers, even the cheaper ones, have automatic timers in order to switch lights on/off at preset times.

The outlets used by transformers are usually outdoor ones, but transformers may also use indoor outlets (in that case, the transformer should be designed and rated for inside use).

Options

The number of garden lights that can be connected to a transformer varies with its capacity. If the transformer is, say, 100-watt, then the total wattage of the lights should not exceed 100 watts (20 garden lights with 5-watt bulbs, for instance).

Besides standard packages, there are other more configurable and less standardized options. If, for instance, you intend to install 10 path lights of 18 watts (180 W) and 2 down-lighting lights of 50 W (100 W), standard packages will not respond to your requirements. But it will be easy to you to purchase a 300-watt transformer – or a larger one to allow future expansions (common capacities range from 150 W to 900 W) - to responde to such needs.

Low voltage cable

Low-voltage cable must be weather-resistant. Typically they begin and end at the transformer (creating a looped run).

Popular sizes include 12-, 14- and 16-gauge (gauge depends on the amount of watts required to operate the system).

Typically, 16-gauge cable can carry 150 watts, while 14-gauge cable can carry 200 watts and 12-gauge - the standard - can carry 300 watts.

Installation & Low-voltage outdoor lighting

Many pre-packaged low-voltage systems are relatively simple and safe to install, geared for the do-it-yourselfer, and do not require a professional electrician.

Just take into account some basic design techniques.

See: Landscape lighting design.